Shop Best Types of Plastic Film in Haimu
In recent years, types of plastic film has become the most popular product of Hangzhou Haimu Technology Co., Ltd.. We pay great attention to the product details and we push the design team to make great technical improvements. At the same time, we're concerned about the selection of raw materials and we eliminated quality problems from the source. Only reliable raw material suppliers can cooperate strategically with us.
To enhance brand awareness, HARDVOGUE has been doing a lot. Except for improving the quality of the products to spread our word-of-mouth, we also attend lots of renowned exhibitions globally, trying to advertise ourselves. It proves to be a very efficient way. During the exhibitions, our products have attracted many people's attention, and some of them are willing to pay a visit to our factory and cooperate with us after experiencing our products and service.
We know that great customer service goes in pair with high quality communication. For example, if our customer comes with an issue at HARDVOGUE, we keep the service team try not to make a phone call or write an e-mail directly to solve problems. We rather offer some alternative choices instead of one ready-made solution to customers.
When using BOPP (Biaxially Oriented Polypropylene) film for in-mold labeling (IML) in injection molding, several challenges may arise during printing, processing, and molding. Below is a detailed breakdown of common problems and corresponding solutions.
1. Printing Issues
Problems:
● Ink adhesion problems: BOPP film has a smooth, non-porous surface, making ink adhesion difficult.
● Ink drying issues: Some inks dry too slowly on BOPP, leading to smudging or incomplete curing.
● Color variation or poor opacity: The ink may not appear as expected due to the film’s transparency or reflectivity.
Solutions:
✅ Use IML-compatible inks, such as UV-curable or solvent-based inks, to improve adhesion.
✅ Perform surface treatment (e.g., corona treatment or primer coating) to increase surface tension and ink bonding.
✅ Choose white or opaque BOPP films for better color consistency and opacity.
2. Static Electricity Problems
Problems:
● Film sticking together: High static charge causes BOPP labels to stick, making feeding and handling difficult.
● Dust attraction: Static buildup attracts dust and debris, which can affect print quality and mold adhesion.
Solutions:
✅ Use anti-static treatments or coatings on the BOPP film to reduce static buildup.
✅ Install ionizing bars in the production line to neutralize static charges.
✅ Maintain proper humidity levels in the production environment to minimize static electricity.
3. Die-Cutting and Label Handling Issues
Problems:
● Poor die-cutting precision: BOPP’s toughness can cause rough or uneven cuts.
● Edge curling: Improper cutting or tension control may lead to curled labels, affecting placement in the mold.
● Film tearing or warping: Incorrect tension during processing can damage the labels.
Solutions:
✅ Use sharp, high-precision dies and optimize cutting pressure for clean edges.
✅ Control web tension in the cutting process to prevent label warping.
✅ Use multi-layer BOPP films that provide better stiffness and stability.
4. Adhesion and Bonding Problems in the Injection Mold
Problems:
● Label shifting inside the mold: If the label does not stay in place, it can cause misalignment or defects.
● Weak bonding with plastic: BOPP film may not adhere well to the injected plastic, leading to peeling.
● Wrinkling or air bubbles: Poor label positioning or excessive mold temperature can cause defects.
Solutions:
✅ Use static charge or vacuum systems to hold the label in place before injection.
✅ Ensure the film is coated with a suitable anchoring layer for better adhesion to the molded plastic.
✅ Adjust mold temperature and injection pressure to minimize air entrapment and improve label integration.
5. Temperature and Shrinkage Issues
Problems:
● Film shrinkage or distortion: High temperatures during molding can cause the BOPP label to shrink unevenly.
● Dimensional stability problems: If the film expands or contracts too much, it can lead to misalignment.
Solutions:
✅ Use high-heat-resistant BOPP films specifically designed for IML applications.
✅ Ensure proper label conditioning before molding to minimize expansion or shrinkage.
✅ Control mold temperature and injection cycle time to reduce thermal stress on the label.
6. Environmental and Storage Problems
Problems:
● Film brittleness in low temperatures: BOPP can become brittle in cold storage conditions.
● Moisture-related issues: High humidity can affect ink adhesion and cause film distortion.
Solutions:
✅ Store BOPP film in a controlled environment with stable temperature and humidity.
✅ Use protective packaging to prevent dust and moisture exposure.
✅ Allow films to acclimate to room temperature before printing and molding.
Summary Table
|
Issue Category |
Specific Problems |
Solutions |
|
Printing Issues |
Ink adhesion problems, slow drying, poor opacity |
Use IML-compatible inks, surface treatments, and opaque films |
|
Static Electricity Issues |
Labels sticking together, dust attraction |
Apply anti-static treatments, use ionizing bars, control humidity |
|
Die-Cutting Issues |
Rough cuts, edge curling, film warping |
Use sharp dies, control web tension, choose multi-layer films |
|
Molding Adhesion Issues |
Label shifting, weak bonding, wrinkles/bubbles |
Use static charge or vacuum systems, adjust mold conditions |
|
Temperature Issues |
Shrinkage, dimensional instability |
Use high-heat-resistant BOPP, control mold temperature |
|
Storage Issues |
Brittleness in cold, moisture effects |
Store in a controlled environment, acclimate before use |
Offering IML-grade BOPP films that are pre-treated for printing, anti-static properties, and high-temperature resistance will improve product performance and processing efficiency.
1. Poor Label Release
Causes:
● Inadequate or low-quality adhesive.
● Incorrect label applicator settings (too much or too little pressure).
● Static electricity causing labels to stick together or release unevenly.
Solutions:
✅ Use a suitable adhesive (pressure-sensitive or heat-activated) for better bonding.
✅ Adjust labeling machine pressure and speed for smoother label release.
✅ Apply anti-static coatings or control humidity to reduce static-related issues.
2. Bubbling or Wrinkling After Application
Causes:
● Air trapped under the label during application.
● Improper tension or pressure in the labeling process.
● Contaminants on the bottle surface, such as oil, dust, or moisture.
Solutions:
✅ Use a flexible BOPP film that conforms well to bottle curves.
✅ Adjust the label applicator settings to apply even pressure across the label.
✅ Ensure bottle surfaces are clean and dry before labeling.
3. Poor Print Quality
Causes:
● Incompatible ink or poor ink adhesion to BOPP film.
● Incorrect printing machine settings, affecting ink distribution.
● Inadequate pre-treatment of BOPP film (such as missing corona treatment).
Solutions:
✅ Choose UV, flexographic, or gravure inks that adhere well to BOPP film.
✅ Ensure BOPP film has undergone corona treatment (surface energy ≥38 dyn/cm).
✅ Optimize printing machine settings, such as pressure, speed, and drying time.
4. Misalignment During Label Application
Causes:
● Labeling machine misalignment or improper sensor calibration.
● High-speed application causing labels to shift or slip.
● Poor flexibility of the BOPP film, leading to misplacement.
Solutions:
✅ Adjust the labeling machine sensors to ensure precise label positioning.
✅ Use a rigid and dimensionally stable BOPP film to minimize deformation.
✅ Reduce labeling speed if necessary to allow better alignment.
5. Edge Lifting or Peeling Off
Causes:
● Environmental changes (temperature/humidity) affecting adhesion.
● Uneven thickness of BOPP film causing shrinkage or curling at edges.
● Incompatible adhesive that fails under storage or transportation conditions.
Solutions:
✅ Choose BOPP film with high moisture and temperature resistance.
✅ Ensure label film thickness is consistent to prevent curling.
✅ Select adhesives suited for specific storage and transportation conditions (e.g., low-temp or heat-resistant adhesives).
6. Inconsistent Shrink Performance (For shrink wrap label films)
Causes:
● Uneven heat distribution in the shrink tunnel.
● Mismatch between BOPP shrink properties and bottle shape, leading to wrinkles.
Solutions:
✅ Use an even heat distribution system (hot air or steam shrink tunnels).
✅ Select the right BOPP film thickness and material to match the bottle’s shrink rate.
Summary Table
BOPP wrap label film issues often arise due to labeling process inefficiencies, material selection, printing compatibility, and storage conditions. To ensure optimal performance:
1. Choose the right BOPP film type (transparent, pearlescent, metallized, etc.).
2. Use compatible adhesives and printing inks.
3. Optimize labeling machine settings (pressure, speed, alignment).
4. Control storage conditions to avoid extreme temperature or humidity effects.